Development of a Soft‐Chemistry‐Based Hydrogen Generator for Dual‐Fuel Diesel Engine

ABSTRACT The rising demand for cleaner energy sources has led to increased interest in hydrogen as a zero‐carbon fuel. This study presents the design and integration of an on‐demand hydrogen generation reactor with a variable compression ratio diesel engine. Hydrogen was produced through a chimie douce (soft chemistry) approach, involving the hydrolysis of nano‐aluminum amalgams formed by reducing aluminum and mercury salts with sodium borohydride under ambient conditions. The generated hydrogen was directly supplied to a single‐cylinder, four‐stroke diesel engine operating in dual‐fuel mode. Engine performance and emissions were evaluated at two compression ratios (14 and 16) with hydrogen flow rates of 0, 1, 2, and 3 liters per minute (LPM) across varying engine loads. Results demonstrated notable improvements in engine efficiency and emission reductions with hydrogen enrichment. At CR 16 and 3 LPM hydrogen flow, Brake Thermal Efficiency (BTE) improved by 13.33%% and Brake Specific Fuel Consumption (BSFC) decreased by 11.76%. Emissions of Carbon Monoxide (CO), Unburned Hydrocarbons (HC), and Nitrogen Oxides (NOₓ) were reduced by 17.4%, 19.62%, and 25.85%, respectively. Similar trends were observed at CR 14, with CO emissions reduced by up to 33.33%. This study highlights the potential of in‐situ hydrogen generation as a practical solution for enhancing diesel engine performance while reducing harmful emissions. The system's compactness and elimination of hydrogen storage requirements make it a viable option for dual‐fuel applications.